Real Climate

JANUARY 16, 2024

Annual updates to the model-observation comparisons for 2023 are now complete. The comparisons encompass surface air temperatures, mid-troposphere temperatures (global and tropical, and ‘corrected’), sea surface temperatures, and stratospheric temperatures. In almost every case, the addition of the 2023 numbers was in line with the long term expectation from the models.

Atmosphere 284

Atmosphere 2023 2022 Ocean 284

Real Climate

JANUARY 12, 2024

As the climate monitoring groups add an additional dot to their graphs this week, there is some disquiet among people paying attention about just how extraordinary 2023 really was. First, it’s been obvious for months that 2023 would be a record year – in temperatures (at the surface, troposphere and in the ocean), in Antarctic sea ice, in the number of big climate disasters etc.

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Ocean 2023 2015 Cooling 332

Real Climate

JANUARY 5, 2024

For the last few years ( since at least 2016 ), I’ve shared predictions for the next annual global mean surface air temperature (GMSAT) anomaly based on the long term trend and the state of ENSO at the start of the year. Generally speaking, this has been quite skillful compared to persistence or just the long term trend alone – the eventual anomaly was consistently within the predicted bounds.

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2016 2017 2024 2023 292

Real Climate

JANUARY 1, 2024

New year, new open thread on climate topics. Note that summaries and updates to include 2023 data will be posted on the surface temperature graphics page and model-observations comparison page over the next couple of weeks as the data becomes available. The post Unforced variations: Jan 2024 first appeared on RealClimate.

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2024 2023 132

Real Climate

DECEMBER 17, 2023

This year’s (2023) tropical cyclone season in the North Atlantic and Caribbean witnessed a relatively high number of named tropical cyclones : 20. In spite of the current El Niño, which tends to give lower numbers. But it appears to follow a historical trend for named tropical cyclones with an increasing number over time. The number of North Atlantic/Caribbean named tropical cyclones in and the estimates based on the area with sea surface temperature above 25.6°C (Benestad, 2009).

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2023 2009 Ocean Sea Level 212

Real Climate

DECEMBER 1, 2023

Well, that year went quickly. This month, there is the COP28 hoopla , the ongoing El Niño and the speculation about the 2023 temperature ranking (which will not be that surprising). An open thread for climate topics… The post Unforced Variations: Dec 2023 first appeared on RealClimate.

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2023 130

Real Climate

NOVEMBER 29, 2023

It is 33 years now since the IPCC in its first report in 1990 concluded that it is “certain” that greenhouse gas emissions from human activities “will enhance the greenhouse effect, resulting on average in an additional warming of the Earth’s surface.” That has indeed happened as predicted, it has been confirmed by a zillion studies and has been scientific consensus for decades.

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Greenhouse Radiation Cooling Carbon Dioxide 300

Real Climate

NOVEMBER 18, 2023

John Clauser’s theory of climate explained. Some of you will have heard of John Clauser because he was an awardee of the 2022 Nobel Prize in Physics for his role in the experimental verification of quantum entanglement. Some of you will have heard of him because the first thing that he did after winning the Nobel was join a climate denial organization and make some rather odd claims about climate science.

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Radiation 2003 2020 Climate Change 68

Real Climate

NOVEMBER 11, 2023

A friend asked me if a discussion paper published on Statistics Norway’s website, ‘ To what extent are temperature levels changing due to greenhouse gas emissions? ’, was purposely timed for the next climate summit ( COP28 ). I don’t know the answer to his question. But this discussion paper is problematic for sure. It was, authored by Dagsvik and Moen, and already in its introduction it claims that it is difficult to explain and predict weather and temperature (giving the false impression that

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Sea Level Greenhouse Climate Change Atmosphere 292

Real Climate

NOVEMBER 1, 2023

This month’s open thread on climate topics. The post Unforced Variations: Nov 2023 first appeared on RealClimate.

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2023 130

Real Climate

OCTOBER 4, 2023

The fifth international conference on regional climate ( ICRC 2023 ), organised by World Climate Research Programme’s ( WCRP ) coordinated downscaling experiment ( CORDEX ), has just completed. It was a hybrid on-site/online conference with hubs in both Trieste/Italy (hosted by the International Centre on Theoretical Physics, ICTP ) and Pune/India.

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2002 2016 2023 2012 197

Real Climate

OCTOBER 1, 2023

This month’s open thread on climate topics. Please try to stay on topic and refrain from posting tedious, oft-debunked nonsense. Look out for more reports of ridiculously high global temperatures and intense rainfall, and more confident predictions of the budding El Niño event and annual temperature rankings… The post Unforced variations: Oct 2023 first appeared on RealClimate.

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2023 130

Real Climate

SEPTEMBER 26, 2023

Media awareness about global warming and climate change has grown fairly steadily since 2004. My impression is that journalists today tend to possess a higher climate literacy than before. This increasing awareness and improved knowledge is encouraging, but there are also some common interpretations which could be more nuanced. Here are two examples, polar amplification and extreme rainfall.

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Ocean Climate Change 2023 Atmosphere 198

Real Climate

SEPTEMBER 21, 2023

It has taken 17 months to get a comment published pointing out the obvious errors in the Scafetta (2022) paper in GRL. Back in March 2022, Nicola Scafetta published a short paper in Geophysical Research Letters (GRL) purporting to show through ‘advanced’ means that ‘all models with ECS > 3.0°C overestimate the observed global surface warming’ (as defined by ERA5).

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2022 2023 2015 Atmosphere 250

Real Climate

SEPTEMBER 6, 2023

The latest contrarian crowd pleaser from Soon et al (2023) is just the latest repetition of the old “it was the sun wot done it” trope[1] that Willie Soon and his colleagues have been pushing for decades. There is literally nothing new under the sun. Before diving into the specific artifices in the latest paper, a little trip down history lane might be fun to set the context… “It’s the Sun” Solar variability as a potential cause for climate change has a long (

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2005 2003 2015 2004 331

Real Climate

SEPTEMBER 1, 2023

This month’s open thread on climate science topics. It’s been a warm summer, dontcha know? Expect ERA5, the satellite data and then the surface data products to confirm this in the next week or so. Sea ice minimum in the Arctic will also occur soon, as will a record low maximum in the Antarctic. El Niño still building in the tropical Pacific.

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2023 130

Real Climate

AUGUST 25, 2023

A few weeks ago, a study by Copenhagen University researchers Peter and Susanne Ditlevsen concluded that the Atlantic Meridional Overturning Circulation (AMOC) is likely to pass a tipping point already this century, most probably around mid-century. Given the catastrophic consequences of an AMOC breakdown, the study made quite a few headlines but also met some skepticism.

Ocean 243

Ocean Fossil Fuels Cooling 2016 243

Real Climate

AUGUST 1, 2023

This month’s open thread for climate topics. Has anyone noticed how warm it’s been? Someone should probably look into that… The post Unforced Variations: Aug 2023 first appeared on RealClimate.

2023 130

2023 130

Real Climate

JULY 24, 2023

For various reasons I’m motivated to provide an update on my current thinking regarding the slowdown and tipping point of the Atlantic Meridional Overturning Circulation (AMOC). I attended a two-day AMOC session at the IUGG Conference the week before last, there’s been interesting new papers, and in the light of that I have been changing my views somewhat.

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Ocean Cooling 2011 2021 246

Real Climate

JULY 23, 2023

The World Meteorological Organisation (WMO) Global Climate Observing System (GCOS) and Copernicus Climate Change Services (C3S) both provide sets of global climate statistics to summarise the state of Earth’s climate. They are indeed valuable indicators for the global or regional mean temperature, greenhouse gas concentrations, both ice volume and area, ocean heat, acidification, and the global sea level.

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Sea Level Ocean Climate Change 2022 179

Real Climate

JULY 8, 2023

You can tell how worried the climate deniers are by how many fields of science they have to trash to try and have people not see what’s happening. it will not have escaped most people’s notice that global temperatures are heading into uncharted territory. The proximate cause of this week’s headlines is the Climate Reanalyzer website at the U. Maine which provides a nice front end to the NOAA NCEP CFS forecast system and reanalysis and shows absolute daily temperatures in early July clearly excee

Ocean 331

Ocean 2016 2017 2023 331

Real Climate

JULY 1, 2023

This month’s open thread for climate topics. Let the (northern hemisphere) heat wave and wildfire smoke season begin! The post Unforced variations: July 2023 first appeared on RealClimate.

2023 130

2023 130

Real Climate

JUNE 4, 2023

The world is full of climate dashboards (and dashboards of dashboards ), and so you might imagine that all datasets and comparisons are instantly available in whatever graphical form you like. Unfortunately, we often want graphics to emphasize a particular point or comparison, and generic graphs from the producers of the data often don’t have the same goal in mind.

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193

Real Climate

JUNE 2, 2023

This month’s open thread on climate topics. The post Unforced Variations: Jun 2023 first appeared on RealClimate.

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2023 130

Real Climate

MAY 31, 2023

Do the global climate models (GCMs) we use for describing future climate change really capture the change and variations in the region that we want to study? There are widely used tools for evaluating global climate models, such as the ESMValTool , but they don’t provide the answers that I seek. I use GCMs to provide information about large-scale conditions, processes and phenomena in the atmosphere that I can use as predictors in downscaling future climate projections.

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Sea Level 2012 Atmosphere 2023 177

Real Climate

MAY 21, 2023

As predicted in 1967 by Manabe and Wetherald , the stratosphere has been cooling. A new paper by Ben Santer and colleagues has appeared in PNAS where they extend their previous work on the detection and attribution of anthropogenic climate change to include the upper stratosphere, using observations from the Stratospheric Sounding Units (SSUs) (and their successors, the AMSU instruments) that have flown since 1979.

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Cooling Ozone Atmosphere Radiation 253

Real Climate

MAY 1, 2023

This month’s open thread on climate topics. Please be succinct, courteous and on point. The post Unforced variations: May 2023 first appeared on RealClimate.

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2023 132

Real Climate

APRIL 23, 2023

What does a new entrant in the lower troposphere satellite record stakes really imply? At the beginning of the year , we noted that the NOAA-STAR group had produced a new version (v5.0) of their MSU TMT satellite retrievals which was quite a radical departure from the previous version (4.1). It turns out that v5 has a notable lower trend than v4.1, which had the highest trend among the UAH and RSS retrievals.

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Atmosphere Ocean 2001 Ozone 237

Real Climate

APRIL 6, 2023

The summary for policymakers of the Intergovernmental Panel on Climate Change (IPCC) sixth synthesis report was released on March 20th (available online as a PDF ). There is a recording of the IPCC Press Conference – Climate Change 2023: Synthesis Report for those who are interested in watching an awkward release of the report. It strikes me that the IPCC perhaps assumes that everyone is climate literate and are up to speed on climate change.

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Climate Change Fossil Fuels Greenhouse 2012 258

Real Climate

APRIL 1, 2023

This month’s open thread on climate topics (no joke). The post Unforced Variations: Apr 2023 first appeared on RealClimate.

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2023 132

Real Climate

MARCH 16, 2023

We add some of the CMIP6 models to the updateable MSU comparisons. After my annual update , I was pointed to some MSU-related diagnostics for many of the CMIP6 models (24 of them at least) from Po-Chedley et al. (2022) courtesy of Ben Santer. These are slightly different to what we have shown for CMIP5 in that the diagnostic is the tropical corrected-TMT (following Fu et al., 2004 ) which is a better representation of the mid-troposphere than the classic TMT diagnostic through an adjustment usin

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2004 Atmosphere Ozone 2022 321

Real Climate

MARCH 5, 2023

A trip down memory lane and a lesson on scientific integrity. I had reason to be reviewing the history of MSU satellite retrievals for atmospheric temperatures recently. It’s a fascinating story of technology, creativity, hubris, error, imagination, rivalry, politics, and (for some) a search for scientific consilience – worthy of movie script perhaps?

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2014 2013 Cooling 2005 261

Real Climate

MARCH 1, 2023

This month’s open thread. Antarctic sea ice anyone? The post Unforced variations: March 2023 first appeared on RealClimate.

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2023 130

Real Climate

FEBRUARY 8, 2023

Science is naturally conservative and the scepticism to new ideas ensures high scientific quality. We have more confidence when different scholars arrive at the same conclusion independently of each other. But scientific research also brings about discoveries and innovations, and it typically takes time for such new understanding to receive acknowledgement and acceptance.

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2001 2005 2017 2011 139

Real Climate

FEBRUARY 2, 2023

Our annual post related to the comparisons between long standing records and climate models. As frequent readers will know, we maintain a page of comparisons between climate model projections and the relevant observational records , and since they are mostly for the global mean numbers, these get updated once the temperature products get updated for the prior full year.

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2022 Atmosphere Ozone Ocean 362

Real Climate

FEBRUARY 2, 2023

This month’s open thread for climate related topics. Please be constructive, polite, and succinct. The post Unforced variations: Feb 2023 first appeared on RealClimate.

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2023 Politics 132

Real Climate

JANUARY 13, 2023

Another January, another annual data point. As in years past , the annual rollout of the GISTEMP, NOAA, HadCRUT and Berkeley Earth analyses of the surface temperature record have brought forth many stories about the long term trends and specific events of 2022 – mostly focused on the impacts of the (ongoing) La Niña event and the litany of weather extremes (UK and elsewhere having record years, intense rainfall and flooding, Hurricane Ian, etc. etc.).

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2022 2016 Cooling 2017 292